Forming of foamed material articles



March 28, 1967 R. MCGEE 3,311,007

FORMING OF FOAMED MATERIAL ARTICLES Filed Sept. 22, 1965 I/VVENTOP.

' R Ma 6'55 United States Patent 3,311,007 FORMTNG F FOAMED MATERIALARTICLES Robert McGee, Cheadle Hulme, Cheshire, England, as-

signor to Vitafoam Limited, a corporation of Great Britain, Isle of Man,and Northern Ireland Filed Sept. 22, 1965, Ser. No. 489,355 1 Claim.(Cl. 831) This invention relates to apparatus for producing a contouredsurface on a foamed material pad or the like, by cutting such pad whileit is held between male and female formers.

In the past when a contoured, for example domed, seat pad has beenrequired it has generally been fabricated by securing together a flatfaced base pad, and for a single domed face, a fiat faced cover pad andlocating therebetween and in the central region of the base pad a fillerpad whose edges have been chamfered. For a pad having two domed faces afiller pad has been provided on each face of the base pad and a pair ofcover pads have been used. Similarly when a more complex contour isrequired fabrication is used.

According to the present invention the apparatus for producing at leastone contoured surface upon a foamed material pad locates the face of thepad in contact with the face of a male former whose surface correspondsto the form required on the pad and applies pressure to the pad in aselected area or areas from its opposite face by means of a suitablyshaped compression member to compress the pad to a greater extent in thehigh regions of the former than the low regions. The apparatus cuts thepad in a straight line, for example with a band knife, and thereafterremoves the pad whereby a greater amount of material is removed in theregions of lower compression than in the regions of higher compression,thus to form a pad having surface of the required contour.

According to a further feature of the present invention apparatus forproducing a foamed material pad having at least one contoured surfaceincludes a male former having a face whose contour corresponds to thatrequired in the pad, a female whose shape is such that varyingcompressive forces can be applied to selected areas of the pad, andmeans for cutting the pad in a fiat plane adjacent the former.

The invention will be described further, by way of example, withreference to the accompanying drawing which illustrates in sideelevation apparatus for forming a domed upholstery pad. In the followingdescription a simple seat pad having two convex domed surfaces will bedescribed but this does not restrict the invent-ion to the formation ofthis type of pad only.

To produce a convex domed seat pad a former is produced and thisconsists of a framework consisting of base members .10 and supportmembers 11 located at right angles thereto. The support members 11 carrya domed male former 12 whose contour corresponds to that required on theseat pad. Movable relative to the male former 12 is a pressure memberwhich comprises a female former 13 carried by slidable rods 14. Theslidable rods 14 are mounted in a framework 15 which latter is mountedon a base 16. Secured to the slidable rods 14 is a pressure plate 17 towhich is attached the ram 18 of a pneumatic cylinder 19. The cylinder 19is securely attached to the framework .15. The female former 13 "ice isflat faced and has a peripheral rim 20, the former 13 thus resembles atray.

The male former 12 is adapted to be secured upon the table of, forexample, a band knife, (generally indicated by the reference 21) bymeans of studs which pass through the base members 10 and the band knifetable 22. The male former is so positioned that its domed surface islocated adjacent to and in a plane parallel to the plane of the knife 23of the band knife 21. The female former 13 is also secured to the bandknife table 22 by means of studs, the position of the former 13 is suchthat it is spaced from former 12 by a distance sufficient to enable anuncut pad 24 to be placed between the formers.

To produce the domed pad the flat sided pad 24 of, for example, foamedpolyether material whose thickness exceeds the maximum thickness of thefinished pad is placed in position between the male former 12 and thefemale former 13. The female former 13 is pushed towards the male former12 by pneumatic pressure from the cylinder 19 so that the face thereofadjacent the male former 12 is subjected to a smaller amount ofcompression around the edges of the male former .12 (the low region ofthe former) than in the centre (the high region) and thus the pad iscompressed to a greater extent in the centre region than the edges. Theband knife table 22 is moved in the usual manner to cause the knife 23to make a straight cut through the pad 24 in such a manner that a smallclearance, in the region of one quarter of an inch, exists between theknife 23 and the highest part of the male former 12.

When the female former is released and the pad 24 is removed and allowedto return to its natural uncompressed condition it is found that the pad24 has a convex domed surface. The pad 24 is reversed and the oifcutretained in position on the pad 24 and the same procedure adopted forthe formation of a convex dome on the opposite face.

The invention is not restricted to the above details. For example, thepad may be produced with concave domed surfaces. In this case the maleformer 12 would be concave in form and greatest pressure would beapplied at the centre of the pad. It is also possible to produce othercontours and irregular doming using the same principle as that describedabove. It is also possible to use a hydraulic ram as opposed to thepneumatic ram referred to above.

The material to be formed may, of course, be other than foamed polyethermaterial and pads 24 other than seat pads can be produced. The padsproduced may have only one, or more than two contoured surfaces.

I claim:

Apparatus for producing a contoured surface on a foamed material pad,said apparatus comprising a band knife including a table and a poweroperated knife adjacent to said table, a stationary male former having acontoured surface mounted on said table and closely adjacent to saidknife, a framework mounted on said table, slidable rods mounted in saidframework, a female former carried by said slidable rods for movementtoward and away from said male member and for cooperatively holding apad to be cut with said male former, fluid operated ram means mounted onsaid framework and attached to said rods for sliding the latter andconsequently the female former in said directions toward and away fromsaid male former, whereby a pad to be cut is held compressed betweensaid formers for cutting by said knife and means supporting the tablefor movement transversely to the direction in which said female formeris slidable.

References Cited by the Examiner UNITED STATES PATENTS 3,154,607 10/1964Struthers 8319 X 4 3,186,271 6/1965 Kaiser 834 3,245,293 4/1966 Kirchner83176 FOREIGN PATENTS 572,515 1/1958 Italy.

ANDREW R. JUHASZ, Primary Examiner.

